Quotes from "Why We Get Fat"

Because the insulin level in the bloodstream is determined primarily by the carbohydrates that are consumed ... it's those carbohydrates that ultimately determine how much fat we accumulate.  Here's the chain of events:

1. You think about eating a meal containing carbohydrates.
2. You begin secreting insulin.
3. The insulin signals the fat cells to shut down the release of fatty acids (by inhibiting HSL) and take up more fatty acids (via LPL) from the circulation.
4. You start to get hungry, or hungrier.
5. You begin eating.
6. You secrete more insulin.
7. The carbohydrates are digested and enter the circulation as glucose, causing blood sugar levels to rise.
8. You secrete still more insulin.
9. Fat from the diet is stored as triglycerides in the fat cells, as are some of the carbohydrates that are converted into fat in the liver.
10. The fat cells get fatter, and so do you.
11. The fat stays in the fat cells until the insulin level drops.

If you're wondering whether any other hormones [besides insulin] make us fat, the answer is effectively no....

- Gary Taubes, "Why We Get Fat," page 122

...cortisol makes us store fat both directly (through LPL) and indirectly (through insulin).  But then it works to release fat from our fat cells, primarily by stimulating HSL, just like other hormones.  So cortisol can makes us fatter still when insulin is elevated, but it can also make us leaner, just like every other hormone, when insulin levels are low.  And this may explain why some people get fatter when they get stressed, anxious, or depressed and eat more, and some people do the opposite.

The bottom line is something that's been known (and mostly ignored) for over forty years.  The one thing we absolutely have to do if we want to get leaner -- if we want to get fat out of our fat tissue and burn it -- is to lower our insulin levels and to secrete less insulin to begin with.

- ibid, page 124

...when you eat sugar, according to research by Bartley Hoebel of Princeton University, it triggers a response in the ... part of the brain ... known as the reward center ... that is targeted by cocaine, alcohol, nicotine, and other addictive substances.  All food does this to some extent, because that's what the reward system apparently evolved to do: reinforce behaviors (eating and sex) that benefit the species.  But sugar seems to hijack the signal to an unnatural degree, just as cocaine and nicotine do.

- ibid, page 142